Viken, Sweden – Välinge Group has developed a new digital printing technology that combines the advantages of ink jet and laser printing. The new technology makes it possible to apply large amounts of pigment-coated particles (“dry ink”) and bond the particles in well-defined patterns with a water-based transparent binder that does not include any pigments (“blank ink”). The new digital Binder And Powder (BAP) printing offers cost advantages, speed and reliability over previous methods.
Digital ink jet printing is a very flexible, non-contact method that may provide a high quality print but cannot be fully utilized in flooring applications due to high cost of ink as well as problems related to clogging of nozzles–especially when pigment-based inks are used–and the need for special base layers that cover the board and protective layers that protect the digital print. The investments are very high since about 160 Piezo print heads are needed to provide a five-color pigment-based print on a 2 mm wide laminate floor sheet.
Laser printing is a contact method that is not used in flooring applications. It is generally faster and more reliable, and the cost for the dry powder-based pigments is lower.
With Valinge’s new technology, as a first step, a conventional print head applies blank ink on a surface. The head may be very simple since only water is applied and there are no problems with clogging of the nozzles. The surface may be a powder layer, paper, PVC foil, tile, wood, textile or similar material.
As a second step, dry ink-comprising particles coated with a binder and pigments is applied on the whole surface and liquid blank ink pattern. The dry ink particles may be minerals such as aluminium oxide or sand, wood fibers, spray-dried melamine, etc. The binder may be a thermosetting melamine resin or thermoplastic resin.
As a third step, non-bonded dry ink particles are removed with a vacuum, and particles bonded by the blank ink form a perfect digital pattern that corresponds to the liquid pattern printed by the digital print head.
The removed dry ink particles are automatically blown back into the scattering station, where they are reused in a new, print-forming cycle. Several colors may be applied with the same blank ink, and a multi-color print may be formed in a very cost efficient way. Välinge will produce blank and dry ink custom made for each application and décor.
Digital BAP printing may be combined with conventional digital printing. BAP technology may be used to apply 90% of the colorants needed for the base colors, and a few spot colors may be applied with conventional ink jet technology. This may be used to decrease the amount of convectional ink to a level of about 2 gr/m2.
Välinge Flooring Technology AB has recently filed nine patent applications related to digital technologies. Several applications are pre-published.